Because of problems with Yosemite, I did a clean install of everything, INCLUDING Microsoft Office, a few months back. It never made any difference to any of the long-standing problems I am experiencing with Word 2011 (not that I had any hope that it would).
The disappearing cursor problems were there before then (they've been there since Word 2004, in fact, as I have documented on my blog, including with video recordings) and they are still there in Word 2011 today. Just because you are not experiencing them
yourself does not mean that they don't exist.
I am also suspicious of people saying that they don't see any problems, because I am someone who works very fast and is particularly sensitive to such issues. I expect 100% responsiveness at all times. People who work more slowly and without trying to use
the full power of their machine might not notice these issues.
Also, such problems are much more evident when editing existing documents than when
composing new documents from scratch, which tend to be very different tasks. I often have to work with existing documents, mostly created by other people on other machines, and that is not the same as creating your own documents, with your
own style sheets, your own settings, etc.